Fe2 Dimers for Non-Polar Diatomic O2 Electroreduction

Non-polar diatomic molecule activation is of great significance for catalysis. Despite the high atomic efficiency, the catalytic performance of single-atom catalysts is limited by insufficient receiving sites for diatomic molecule adsorption. Here, Fe-2 dimers were successfully synthesized through precisely regulating the metal loading on metal-organic frameworks. The unique role of metal dimers in activating diatomic O-2 molecules was explored. In alkaline electrolytes, the specific oxygen reduction reaction activity of Fe-2 dimers was 7 times higher than that of Fe-1 counterparts. The hydrogen atom transfer probes indicated a different activation mode for O-2 on Fe-1 and Fe-2 dimers, respectively. Theoretical calculation results revealed that Fe-2 dimers opened up a new reaction pathway by promoting the direct breaking of O=O bonds, thus avoiding the usual formation of *OOH intermediates, which helped explain the lower H2O2 yield and higher specific activity.

Automated summary

The synthesis of Fe-2 dimers has been found to effectively activate non-polar diatomic molecule O-2 and enhance its catalytic activity. Additionally, Fe-2 dimers promote the direct breaking of O=O bonds, leading to lower H2O2 yield and higher specific activity.